I don't know if it's an issue with the rpi or not, but I know that SD cards can draw current in short spikes during writes and need a good supply with good deco

I don't know if it's an issue with the rpi or not, but I know that SD cards can draw current in short spikes during writes and need a good supply with good decoupling capacitors so there's not voltage drops, as these can cause corruption. In an embedded device I've designed (with careful capacitor selection), I've very rarely had any SD card issues (3 corruption cases in ~1000 devices over a couple years). I'm using Sandisk and Samsung class 4, 6 or 10 (depending on availability).